In what promises to be the music event of the summer featuring the biggest international stars in hit music today, those four artists will be joined by Kelly Clarkson, Ed Sheeran and Jessie J.
This year's Summertime Ball line-up also features Example, Flo Rida, Pitbull and The Wanted, who will perform at the event for the third year in a row.
The Summertime Ball 2012 line-up is:
Tickets for the fourth edition of the event go on general sale on Monday (23rd April 2012) at 8am.
If you're a Capitalfm.com VIP or a Vodafone customer, you can get access to an exclusive tickets pre-sale now.
Keep your eye on the ball by visiting our special Summertime Ball (#STB) area for all the latest information on this year's hit music event.
You can also follow all the action by liking Capital FM on Facebook and Twitter using the official hashtag #CapitalSTB.